Monday, 18 January 2016

Guinness’s Park Royal Brewery in 1949 – the hop stores

We’re finishing our look at the first of the five blocks in Guinness’s Park Royal brewery. Featuring the other main raw material, hops.

“The Hop Stores.—There are six hop stores with a total storage capacity of 950 tons. Each is a steel-framed, brick-pannelled building, the steel staunchions being encased in concrete with chamfered corners to prevent damage to the hop bales, the floors of the stores being covered in hard-wood blocks laid on the concrete. These stores were designed to provide conditions necessary for satisfactory storage of hops, i.e. cool and dark buildings with a minimum movement of air. Each store is about 23 ft. high by 130 ft. long by 60 ft. wide, and each floor is designed for a load of 2.5 cwts. per sq. ft. ”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 281.

950 tons is an Imperial shitload, over 2 million pounds. Guinness was relatively heavily hopped, but I doubt at more than 2 lbs per barrel. Meaning they had the capacity to store sufficient hops to brew more than 1 million barrels, i.e. more than a whole year’s output.

Buying more hops than you needed in years when they were cheap was common practice amongst British brewers in the 19th century. Hops are an extremely delicate crop, with the harvest, and accordingly the price, varying greatly from year to year. So I don’t find it odd that Guinness had such a large hop store.

This is how they packed the hops into the silos:

“The hop bales, handled into and out of the store by bale elevators, are stacked up to 18 ft. high with 18-in. walk-ways between, which brings them within about 2 ft. of the top of the store. Stacking is carried out by means of an "iron man," an electrically-operated lifting jib on a travelling platform. Although this has proved satisfactory, in future we would probably be favourably inclined towards an overhead travelling crane with the lifting carriage "nested" inside the crane frame to reduce head clearance. Experience up to the time of designing Park Royal indicated that there was no marked economic advantage in artificially cooled hop storage, as the risk of possible deterioration of the hops due to temperature rise in a hot summer was more than outweighed by the heavy capital cost of the cooling plant. Consideration of the problem to-day and the relative costs might well decide in favour of the artificially cooled store.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 281.

I’m surprised that they hadn’t considered artificial cooling of the hop stores necessary. The cooler you keep hops, the slower they deteriorate. I suppose it all depends on how cool the stores were naturally.